A variety of diseases exists that require regular treatment by injection of a medicament. Such injection can be performed by using injection devices, which are applied either by medical personnel or by patients themselves. As an example, type-1 and type-2 diabetes can be treated by patients themselves by injection of insulin doses, for example once or several times per day. For instance, a pre-filled disposable insulin pen can be used as an injection device. Alternatively, a re-usable pen may be used. A re-usable pen allows replacement of an empty medicament cartridge by a new one. Either pen may come with a set of one-way needles that are replaced before each use. The insulin dose to be injected can then for instance be manually selected at the insulin pen by turning a dosage knob and observing the actual dose from a dosage window or display of the insulin pen. The dose is then injected by inserting the needle into a suited skin portion and pressing an injection button of the insulin pen.
To be able to monitor insulin injection, for instance to prevent false handling of the insulin pen or to keep track of the doses already applied, it is desirable to measure information related to a condition and/or use of the injection device, for example, one or more of the injected insulin type, dose and timing of the injection, in a manner that is reliable and accurate.
Data collection techniques may also be used for purposes other than monitoring insulin injections. For example, data may be collected in order to monitor injections of other medicaments, other medical activities, such as the taking of tablet medication by a patient or infusions, or for non-medical purposes, such as the monitoring of equipment and/or its operation in a home or industrial environment for safety reasons.